<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>box-shadow绘制图片</title>
        <style>
            * {
				margin: 0;
				padding: 0;
				box-sizing: border-box;
			}
			body {
				height: 100vh;
				display: flex;
				align-items: center;
				justify-content: center;
			}
            .preview-img {
                width: 200px;
                position: absolute;
                top: 100px;
                left: 50px;
            }
            .shadow-img {
                width: 1px;
                height: 1px;
                position: absolute;
                top: 100px;
                left: 300px;
            }
        </style>
    </head>
    <body>
        <input type="file">
        <button class="generate">生成HTML</button>
        <img class="preview-img" src="" alt="">
        <div class="shadow-img"></div>

        <script src="index.js"></script>
    </body>
</html>